import java.util.HashMap;

public class Test {

    public static boolean isUnique(String astr) {
        int bitSet = 0;
        char[] s = astr.toCharArray();
        for(char x : s) {
            /*if (bitSet & ((1 << (x - 'a'))) == 0) {
                bitSet |= (1 << (x - 'a'));
            } else {
                return false;
            }*/
        }
        return true;
    }

    public int[] countBits(int n) {
        int[] ans = new int[n + 1];
        for(int i = 0; i <= n; i++) {
            int count = 0;
            int x = i;
            while(x != 0) {
                x &= (x-1);
                count++;
            }
            ans[i] = count;
        }
        return ans;
    }

    public static void main(String[] args) {
        isUnique("abb");
        HashMap<Integer,Integer> map =new HashMap<>();
    }
}
